1. Field of the Invention
The present invention relates to a device for a vacuum cleaner having a hose connected between a vacuum cleaner housing and a tube handle, the tube handle being connected to a nozzle by means of a tube shaft. The present invention also relates to hand-held vacuum cleaner units having a vacuum cleaner housing and an inlet tube, the inlet tube being connected to a nozzle by means of a tube shaft.
2. Description of Related Art
Vacuum cleaners are commonly provided with a hose and a tube handle. In order to adapt the length of the tube shaft to the operator, it is common to use tube shafts comprising an inner tube and an outer tube which can be moved and locked in different positions with respect to each other. Such devices are described, for instance, in EP 293518, 399177, 520534, 552481, 553482 and 537457.
In the last-mentioned specification the telescopically adjustable suction pipe comprises an inner pipe with an axial guide slot having a number of axially-spaced locking notches which receive a locking element that is incorporated into a guide piece fitted in an opening in the other pipe to lie between the inner and outer pipes. The outer pipe has a uniform diameter, the guide piece fitting radially through the opening and being secured against radial movement by a sleeve fitted around the outside of the outer pipe. Preferably, a spring-biased retaining element between the sleeve and the guide piece is displaced via a manual operating element to release the locking element for relative adjustment of the telescopic pipe.
Unfortunately, the devices disclosed in the aforementioned patents are typically difficult to adjust during use because the adjustment mechanism is placed far down on the tube shaft. The location of the adjustment mechanism requires the operator to release his grip about the tube handle and use both hands for moving the inner and outer parts of the tube shaft with respect to each other. Moreover, the known tube shaft arrangements cannot, in a simple manner, be provided with an electric cable or wire which is joined to the shaft and which connects a motor driven nozzle with the electric source of the vacuum cleaner because of the movement between the inner and outer parts of the tube shaft.
Recently, a new type of vacuum cleaner comprising a small hand-held unit has been developed. The hand-held unit comprises a combination of a vacuum source driven by a high speed electric motor and a dust container which is connected directly to a tube shaft. This type of vacuum cleaner is described, for instance, in PCT/SE94/00002 and PCT/SE94/00003.